‘’Evaluate the extent to which the pattern of global atmospheric circulation control weather and climate’’
The Tri-Cellular Model of Atmospheric Circulation shows how energy is redistributed across the globe and ensures there is not a surplus at the equator and deficit at the poles, which would be caused by the differential heating of the Earth’s surface by the Sun. The tri-cellular model is made up of three different air masses which control atmospheric movements and the redistribution of heat energy. The three air masses, starting from the equator, are called the Hadley cell, Ferrel cell and the polar cell.
Basic global atmospheric circulation comprises of three different cells, mirrored either side of the equator, the Hadley Cell, Ferrel Cell and Polar Cell. They help regulate global temperatures and are responsible for air currents in the upper atmosphere. The Hadley cell is an air circulation that has rising air at the equator and descending air approximately at 30 degrees North and South of the equator. They are responsible for the trade winds in the topics and control low-altitude weather patterns. The Hadley Cell affects the climate between the equator, which is tropical and 30 degrees N and S of the equator however, this climate is much drier as a lot of the moisture in the air has already fallen at the equator, which means that the climate around the tropics is incredibly dry. Insolation from the sun causes evaporation of moisture at the equator. This then rises and cools according to the adiabatic lapse rate where it cools at 5.4 degree every 1km. Once it reaches the dew point, it condenses and forms large cumulonimbus clouds. Much of the moisture falls as precipitation and any that are left, release latent heat and carries on rising to the stratopause, which is found 14km high. Here it diverges left and right of the equator and cools and sinks. As this air sinks, it warms up due to conduction where the atoms are getting closer to together due to...